From:	"Jesper de Jong" <niemand AT nergens DOT xs4all DOT nl>
Newsgroups:	comp.lang.c++,comp.lang.c++.moderated,comp.os.msdos.djgpp
Subject:	Re: Using one copy of class for many other classes
Date:	27 Jun 1997 21:55:29 -0400
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scochran AT shoalsnet DOT com schreef in artikel <5p0epd$gtj AT netlab DOT cs DOT rpi DOT edu>...
> In C++ I've run into yet another brick wall.  I have a class called arena
> that is a 50x50 arena for obstacles and robots (for now anyway).  I'm
> running into problems because I only want to have one copy of the arena
and
> multiple copies of the robots or whatever I want to put.
> 
> Would I do it something like this?

Have you ever heard of pointers?? Understanding pointers is *essential*
when you want to program in C or C++.

> int robot::robot(arena arenacopy)

Constructors do not have return values (not even void), so the "int" here
is illegal.

If each robot needs a pointer top the arena it's in, just add a pointer to
the arena member variable in class robot:

class robot
{
private:
    arena * pArena;

public:
    robot(arena * ptr);
    int robofunction();
// the rest of robot here...
};

robot::robot(arena * ptr) : pArena(ptr)
{ }

If you don't understand all this, you need to learn some more C++. Study
some good books or take a course.

> int robot::robofunction(void)
>   {
>    arenacopy.arenafunction();
>   }

int robot::robofunction()
{
    pArena->arenafunction();
}

> Would this work?
> 
> Also I have an enum to define the objects in a buffer of the arena would
it
> be best to derive a class from arena and put all the enum and enum
specific
> (the ones that use the enums) functions there?

Take a C++ course and reconsider your design.

> <TIA>
> Micah Cochran
> scochran AT shoalsnet DOT com

Jesper

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